Syncing contacts seems like it should be fairly straightforward; after all, you're just shuffling around digital business cards. There are some complications involved however. What fields do you sync, and what custom fields can you add on either end of the sync? What happens when third parties need to tack on additional fields?

Apple considered some of these problems back at the original launch of Mac OS X, which debuted with a new Address Book application. Many wondered why Apple was eating into the market for contact managers, as many users at the time already had their contacts in Palm Desktop (formerly Apple's own Claris Organizer), Microsoft's Outlook Express or Entourage, or various other third party tools.

Centralized contacts was a new idea for a desktop OS. As time went on, the logic behind putting everything contact-related in one place became increasingly obvious. It allowed third party developers to draw upon that central pool of contacts, update them, and even add fields, without the mess of each program using its own contact database and then being unable to export or import from others. By that time, Microsoft had designed multiple contact managers on the PC, with at least one for Outlook and one for Office and some clumsy connections between them. Apple's unified Address Book turned contact management into a streamlined OS-level service that was able to later tie into Sync Services. The idea was good enough to be adopted by Windows Vista in the new Windows Contacts.

Address Book on Mac OS X displays a number of default fields (below right), and allows you to add additional fields, such as adding an anniversary, phonetic name, job title, nickname and so on (below left, the Add Field popup list). Developers can also add their own data to the contact pool that Address Book draws upon, although those fields won't show up in the Address Book app. FileMaker's Bento does this, as does Marware's Project X. MobileMe syncs Address Book's contacts up to the cloud and pushes updates back down to the iPhone. Photos added from the iPhone's camera, as well as photos attached in Address Book, are also synced up.

Missing in contacts

There's no way to select only a subset of specific contact groups you'd like to sync with MobileMe. This is a feature drop compared to regular iTunes syncing, which allowed you to sync specific groups. Where would you configure which contact groups to sync? Some users might want to sync all their desktop contact groups to MobileMe, but only a specific subset to their iPhone. This would require some interface complexity in System Preferences : MobileMe, or a settings interface within the Contacts web app, or a setting in Address Book, as iTunes is no longer managing contact sync under MobileMe.

Another rough spot for contacts on the iPhone is that it's not always brilliantly easy to create a new contact or add a phone number to an existing contact. For example, Safari, Mail, and some other apps hyperlink numbers that look phone numbers, but if you tap them, you only have the option to dial the number. There's no way to add the number as a new contact, add it to an existing contact, or use it to start a new SMS. On the other hand, once a number has been dialed you can, from a recent calls listing (below), either call, text message, create a new contact, or add to an existing contact. It would be nice to have those options without actually making a call first.

There is at least one field supported on the iPhone that does not show up in Address Book on the desktop: a Ringtone field. The resulting problem is that when you sync, the settings you've entered on the iPhone for custom ringtones may be wiped out. Some additional fields that can be added in Address Book are not synced to the phone, such as the "friend's name" field. Other optional fields such as job title are synced and display on the iPhone. If you select Add Field from the iPhone's contact edit screen (below), you can find a list of optional fields that are supported by MobileMe sync. Fields in Address Book outside of that list won't sync, but "friend" and "maiden name" seem to be the only non-synced fields.

In the other direction, the IM fields in Address Book do not show up on the iPhone, but are synced up and visible from the MobileMe Contacts web app. Of course, there's currently no use for having IM fields on the iPhone, as Apple does not provide its own iChat for the iPhone, and IM apps such as the free AIM client download your buddy list from AOL's servers rather than accessing them from Contacts on the iPhone. This also means your friendly names you see in iChat are missing from AIM on the iPhone, and you have to remember their AIM handles.

The iPhone maintains a recent call listing that appears to tag the contact listing with the time and date of calls, but this data is not synced back to the desktop Address Book either. We'd like to see this as an option as a way to audit and keep track of your phone calls over time. Also missing: there's no way to create a new contact group on the iPhone or to move a contact to an existing group. You also can't address emails to a contact group as a mailing list.

One last problem between Address Book and the iPhone is that Address Book only has a global preference for mailing address format, which assumes all of your contacts are from the same country. The default US format supplies a Country field, but entering a different country has no impact on how the address is displayed; you still get City State Zip. On the iPhone however, you can't type in a country name; you have to select it from the list of around 60 countries. When you select the country, it reconfigures the address to that country's standard, such as Postal Code City State for Mexico or City County Post Code for the UK (below). Address Book should work the same way (and perhaps intelligently fill in the Zip for you, or the City and State from a Zip, as long as we're asking for things). International iPhone entries sync over to Address Book with their formatting intact. Address Book entries may show up defaulting to the US on the iPhone however.